Stethoscope.



UNITED STATES PATENT OFFICE.

ROBERT C. M. BOWLES, OF BROOKLINE, MASSACHUSETTS.

d. sTETHos'coPE.

SPECIFICATION forming part of Letters Patent No. 677,172', dated J' une 25, 1901.

Application tied' December a, 1897. serai No. 660,575. (No more.)

fication, like letters on the drawings representing like` parts.

This invention relates to stethoscopes of that class shown and described in United States Letters Patent No. 526,802, granted to me 'October 2, 1894, and is arr improvement thereon.

In the practical application of a stethoscope it is of frequent urgency that neither should the patient be raised nor the bedclothing be removed and that all exposure of the person should be avoided as far as possible. These results cannot be satisfactorily accomplished `with stethoscopes as now constructed and known to me; and my present invention has for its object to providean instrument with which these desirabili-ties can .be accomplished.

This invention further has for its object to construct the instrument in a manner, as will be described, whereby the above-mentioned desirabilities may be accomplished with an amplication kand more distinct delivery of the sound-vibrations.

In accordance with this invention the back of the instrument is ,provided With a sounddelivering tube or pipe, preferably of metal, hard rubber, Wood, or other material vor combination of materials not easily compressible, extended substantially parallel with the plane of the diaphragm, so that the depth of the instrument is substantially'small and preferably about one-half an inch. The sound-delivering tube or pipe is preferably curved and `joined to the back of the instrument at its center, whereby the sound ,has an unobstructed and Asmooth passage through said tube which avoids diminution of the sound. The instrument proper is composed of the back referred to and a diaphragm secured or attached thereto and forming the front of the instrument. The back of the instrument is slightly concaved on its front face, so as to form with the diaphragm a shallow air-chamber, which is preferably only of sufficient depth to permit of the free vibration of the diaphragm. The shallow air chamber referred to coperates with the construction of the delivery tube or pipe, so as to enable the lcompleted instrument to be of minimum thickness or depth, and thereby enable it to be used without removing the bedclothing and without raising the patient, as it can be passed between the unremovcd clothing and the body of the patient and can even be passed beneath the body of the patient. The sounddelivery tube is connected to the usual binaural tubes by aliexible tube of any desired length which serves to permit of the use vof the instrument Without removing the clothtion to be referredto.

Referring to Fig. 3, -A represents the back l or base, preferably made in circularform and provided with a concave front face a, which is made on a substantially large radius to form with the diaphragm a a shallow airchamber a2, the diaphragm o1.' being detachably secured to the back A, as herein shown, by means of a ring or cap a5, which is attached to thevback Ain any suitable manner. The air-chamber a2 is provided With an outlet pipe or tube b, which in accordance with this invention extends from substantially the center of 'the back A toward the outer edge of the same and substantially parallel therewith and to the plane in which the diaphragm is held, so that the said tube lies in close proximity to the said back. The tube or pipe bis preferably curved where it joins the back A in order to avoid angles which Would tend to diminish the sound. The tube b is joined by a flexible section of tubing b2 With the usual tube b3, having the branches b4 b5,\vhich lead to the ears of the user. y

By an inspection of the drawings it will be IDO seen that the instrument possesses the advantages and functions above set forth. The instrument may be provided with a centering or localizing point h6, Whichmay be screwed into a hub or projection 19,7 onthe back A when not vin use and which may be screwed into a suitable opening Vin the diaphragm as represented by dotted lines,Fig. 3.v

I prefer to make the outlet tube or pipe'b of metal, hard rubber', or other material'or combination of materials not easily compressible; but` I do not desire to limit my invention in this respect, asthe said outlet tube or pipe may be made of substantially exible material and When in use held subvstantially parallel to the back of the instrument by means of hooks b1 or like devices attached to the back of the instrument after the manner shown in Fig. 4. So, also, Iprefer to make the sound-delivery pipe curved Where it joins the back A, as I have found by erates to form an air-chamber, and asubstantially small curved, non-compressible outlet. or sound delivery tube or pipe attached to said back to communicate With said air-chamber near its center and permanently extended toward the outer edger of said back substantially parallel to the plane in which the diahragm is held, as and for the purpose sp'eci- 2. As an improved article of manufacture, a stethoscopic instrument provided with an exposed diaphragm adapted to make contact with the body of a person, and with a back having a concaved front face with which said diaphragm coperates to form an air-chamber, and a-substantially small curved sound delivery tube or pipe of substantially noncompressible material attached to said back near its center and extended toward the outer -edgeot'said back to afford a smooth and unobstructed outlet for the sound -vibrations from said chamber,substantially as described. 3. As an improved article of manufacture,

a stethoscopic instrument provided with a' back A vhaving its front face a made in the arc of a circle of substantially large radius and a diaphragm a attachedto said back to form a shallow air-chamber ft2 of a depth only sufficient to permit of the free vibration the diaphragm is held, substantially as de' scribed.

4. As anl improved article of manufacture, a stethoscopic instrument provided with a diaphragm and with a back or base having a concaved front face with Which said diaphragm coperates to 'form an'air-chamber, and an outlet or sound delivery tube or pipe attached to said back near its center to communicate with said air-chamber and permanently extended toward the outer edge of said back substantially parallel `to tne plane in Which the diaphragm is held, for the purpose specif tied. 5. As animproved article of manufacture, a stethoscopic instrument provided with a back or base having cooperating With its front face a diaphragm to form anair-chamber, and provided with a substantially small sounddelivery passage communicating With the said air-chamber substantially near its center and extended toward the outer edge or rim of said back orv base substantially parallel to the plane otv the diaphragm, for the purpose specified.

In testimony Awhereof I have signed my name to this specilication inthe presence of two subscribing Witnesses.

ROBERT o. M. BoWLEs.

Witnesses: Y

JAs. H. CHURCHILL, J. MURPHY. 

